Telephone receiver



1617,620 Feb. 15, 1927. J. ERICKSON TELEPHONE Rncrvm Filed Aug. 10. 1923 4 Sheets-Sheet l FILI' n n. Jahn .Erzclsam Feb. 15, mi. ERICKSON 1`,617`,62j

TELEPHONE RECEIVER Filed Aug. 1o, 192:5. sheets-sheet s IHUEH DJs- J: n Erznksnn l 1,617,620 J. ERICKSON TELEPHONE RECEIVER Filed AuiLlO. 1925 4 Sheets-Sheet 4 Patented Feb. 15.,- 1927.

UNITED STATES J'OH'N ERICKSON, 0F. CHICAGO, ILLINOIS,

PATENT OFFICE.

.AUTOMATIC ELECTRIC INC., 0F CHICAGO, ILLINOIS, A CORPORATION OF. DELA- WARE.

` TELEPHONE BECEIVEB.`

Application led August 1o, 1928. Serial 110,656,668.

' The present invention relates to telephone receivers in general, but is concerned more particularly with loud speaking telephone receivers; and thebroad generalobject is' the production of a new and' improvedfloud speaker 'comprising a lnew and .improved` loud spealng telephone receiver together with the container and the necessary associated parts, all of which areof exceedingly simple design and of rugged, construction.

Another object is to so design the receiver and its container that the receiver can be mounted conveniently therein.

A further feature of novelty resfdes in the arrangement of a flange, located at the :mouth of the container, against which the receiver fits on oneside and against which the base'of the horn ts on the other side so asto makeN a good connection betweenl the two without the possibility of the receiver being jarred unduly or forced out of adjust-l ment when the horn is placed in position.

. Another object of the invention is the production of a new and Aimproved mechanical construction whereby the soft iron. pole pieces and the permanent magnet of the receiver cooperate to make a low reluctance magnetic path to' the ends of the soft iron pole pieces. n

A further feature of improvement is the provision of an adjusting screw whereby one of the' soft iron pole pieces may be raised or lowered as the case maydemand, in order to bring its surface on the line with the 'sur-l face of theother pole piece. This enables the slight mechanical imperfections which :rise during manufacture to be compensated There are various other minor features of improvement which will be brought out in.l

the detailed description which is to follow.

tre drawn at right` angles to the plane of the paper on which Fig. 1 is drawn, and .is drawn with the loud speaker held in the'position of Fig. `Land as seen when lookingjn' the direction of the varrow A.

2 is a full sized drawing of the loud I er part of the horn cut Fig. 4 isa bottom view of the loud speaker with the base .and the transformer re'- moved. In this view, the rear of the loud speaker is at the bottom and the front'is at Fig. 5 is a top view` of the loud speaking `receiver-with the 'diaphragm and the ca'p 33 'removed and with certain parts cut away to give a better view of the parts underneath. The front part of the receiver is shown at the top and the rest -at the bottom.

Fig. -6 is a side elevation of the improved diaphragm as it appears before 'being' clamped in place in thereceiver.

Fig. 7 is a cross section through theadjusting member 46 and the spring 47, together witha section of the'container 2, and

` A further feature of novelty relates to the is drawn on the line XX, Fig. .3, as seen from improved adjusting means whereby the dis- 'tance between the'. pole pieces and diaphragm may be variedat will.

A further feature .of novelty resides inthe .improved friction device which retainsthe` The construction of the improved loud speaker will benow explained a little more indetail. The parts are so designed that the receiver, whichcomprises the cylindrical f shell'19, Figs. 2 and v3, together with its con- .tents and the -compound diaphragm andthe cap afterthe said partsvhave been properl as- .sembled as follows.L The diaphragm s own in Fig. 6 is placed upon the v-shell 19. and isf clamped Ybetween the shell and the cap 33 by means of the screws 51 and 52, Fig. 2, 53 and "so, L

maybe mounted Vinside the container 2 -1 54, Fig. 3, and others which are not shown. The diaphragm when thus clamped assumes the ositionshown in Figs. 2 and 3.

ing washer59, and the nut 26 is insulated from the plate l21by the piece of insulation il, whose shape maybe seen most clearly in The ermanent magnet 22 may next be placed 1n position and is held by means ofthe machine screws 60 and 61, Figs. 4 and 5', and the nuts 62 and 63, Fig. 5.

The adjusting screw64, Figs. 2, 4 and 5, may next be screwed in until the end thereof is vflush with the top of the plate 21, as

shown in Fig. 2.

The two soft iron pole pieces 23 and 24 on vwhich the windings29 and 30, Fic'. 2, have be placed: -in the position most clearly shown in Fig. 5.

previously been placed may ,next

As may be seen in Fig. 3, the pole piece 24 rests on a foot or extension at either end.

-TheVpole piece 23 is made in the same way.

The feet of the soft iron pole pieces which are beneath the bobbins 29 and 30 are placed 1n a pair of notches in the insulated member 27, one of which vmay be seen in Fig. 5, di-

rectly -over the end screw 64.

The spreading member 50f maynext be dro ped into place between the outer ends of t e soft iron pole pieces. The washer 49 1s next placed over the said spreading member 50, after which the screw 48 is placed in position and screwed down so as `to hold the entire assembl together. The screw 48 is not turned tig tly at-irst and the-adjusting screw 64 is turned in or out in order to bring the tops of the pole piece 24 'even with .the'top of the pole piece 23. This'adjustment obviates the necessity 'of the usual 'i practice of grinding down the magnets after the assemb y 'is complete. grlndlng down process is practically a neces'- 'sity due to mechanical imperfections in manufacture,and the attempt to level up the'pele pieces in this manner results in line yparticles of iron clinging to the pole pieces which can be removed only with diiiiculty, It is frequently the case. that one or more small particles of iron lare left clinging to the pole pieces which, as is well known',

greatly impairs the eiiciency of the receiver.

The grinding down process is furtherl objec'.`

of the adjusting Otherwise, the' tionable as it often hardens the surface of the iron thereby making it less 'ermeabla In this case, however, since the a ove men-- tioncd means is provided for bringing-one. pole piece to the same height as the other, no

grinding down process is necessary for that purpose. After the pole pieces have been leveled up by means of the adjusting screw 64, the

spreading member 50, which 'has a hexagonal clamping member 20 which can be seen most clearly in Fig. 4 is next screwed `onto the plate 21 by means of the screws 57 and 58. The main part of the member 2() is spaced from the plate 21 by means of the washers 81 and 82, while the arms 83 and 84 press firmly against the plate 21 due to,havin been tensioned previously. The plate 21 with the parts assembled thereon as described above is next screwed into theshell 19 as shown in Figs. 2 andl 3. Before the soft iron pole pieces have reached the diaphragm, the p ate 21 comes flush with the bottom ofthe shell 1.9, and as the plate 21 is turned instill further, the arms 83 and 84 slide along and press .againstthe shell 19 loo and are left behind by the plate 21, thesey arms serving to hold the plate 21 rigidly in y any posit-ion in'which it is left.

The plate 21 and its assembly are l turned still further until the diaphragm is seized by the pole pieces which manifests itself by a faint .but sharp click. .The plate 21 isv then backed off just enough to permit the diaphragm to be released. The receiver isl now completely assembled and is ready to be placed in the container.

v In order to prepare the container 2 for the reeeptionofl the receiver and the horn,- the'ru'bber gasketsi34 and 36, Figs. 2 and 3, are.placed 1n position on either side ofthe ange 35 in 'the throatl of the container, 2.A

It nom remains only to vplace the adjusting member 46 and its retaining spring 47 linto position, the said vspring fitting into a .suitable groove in the'adjust1ng\member 46, as ma be seen in Figs. 3 and 7. The

Ilncipal unction of the spring 47 is to hold the member 46 tight to prevent it from rattling and givin off undesirable sounds when the loudV spea er'is in operation.

The receiver, having been assembled and havlng' receivedits preliminary adjustment as described above2 is n ow placed in the container in thepositlon indicated in Figs. 2, 3, and 4, with the exception that the adjusting placedin the container,

segment 2e is not in the saaie position relanected are neat connected by' means if a tive to the adjusting -member when' the repair of wires (not shown) to the terminals ceiver is iirst placed thel container, on ac- 45 and 25 of the receiver, which terminals count of the fact that it isshown 1n Fi 4 maybe seen best in Figs. 3 and 4. These as having alreadybeen linallyadjuste in accordance witha particular deslred volume. -Instead, when the receiverv is. first` the left hand edge of the segment is'all the way around to the left and lies against the'edge of the washer 18.` Accordmgly the only adjustment that can be ma e from this position is one whichv brings the plole pieces still farther away from the dap ragm. This is de-y sirable on account ofthe fact., as above; stated, the pole ieces are already adjusted as close to thev iaphragm as' the can be placed without an actual seizure o the dia-I phra In order to hold the receiver in place, thewa'shers 17 and 18 are placed in position, after, which the 'bolts 13 and 14, Figs. 2 and 4, are screwed' in ti htly thereby clamping .the shell 19in place, eavmg the plate 21 with its attached parts free to turn inside` the -shell 19 exce t for friction which Vis made considerable y the pressure of the arms 83 and 84 against ,the bottom .o1 lthe shell 19.

The transfqrmer and its mounting maya be next assembled. The terminal mounting strip 43,' Figs. 2.and 3,` has four screw terminals mounted thereon, ask shown in Fig.

2. 'Two'ofthese are used as terminals for the incoming flexible two' conductor cord,A

wires, it may be stated, are referably soldered to the terminals 45 and) 25 while they may be fastened to the binding strip 43 by means of screws thereon. It now remains to bring the flexible two conductor cord (not shown) in through the hole 7, Figs. 1, 3 and 4, in thev container 2 and connect it under the two remaining screws in the terminal ,strip 43.

The base `9 together withl the felt cover 8 i and the iron retaining ring 10, Figs. 2 and 3, may now be secured to the container bymeans of the-'screwll which passes through a hole in the felt covering of the base 9 and through. 'a hole in the base 9 and is screwed into a threaded hole in the transformer mounting bracket 12.

4 In order to complete the-assembly it is only necessaryvto insert the'metal tip 4 of ythe horn 3 in the hole in the top of the container 2, so that the metal tip 4 rests on the rubber gasket 36, after. which thescrew 5' of ig. 1.

The loud speaker may now be connected in a suitable circuit and the finaladjustment ot the distance between the-diaphragm and the pole pieces "is then made. This is laccomis ti htened to hold the horn in the position lished' -by inserting an ordinary 'screw iver lor a similar device into the slot inl and the other two are used as terminals for the .headof the adjusting member 46, Fig. thewire leading from the secondary of the 3, after whichl the member may be turned the transformer to the receiver. Ihe terminal ,correct amount to bringthe receiver into the mounting strip43 and the laminated trans' former core 40, together with the two spac-y ingfsleeves .41 and 42 are clamped to the .screws 37 and 38, which 'cooperate with *threaded hole'sin the bracket 12. Fig.':3

. shows a cross section of the primar and 45" v secondary windin of the .trans ormer i which are both indicated lby the ,referenceA numeral 39. There is af'spac'er 44 which bracket 12 -by ,means of the two machina fpoper position to give it the desired space tween-,the pole pieces and the diaphragm. For the average case kthe osition indicated `in Fig. 4 isabout correct. t may be pointed out that it is impossible to injure the receiver by'fturnin' the adjuster too far in .either direction, t e se ment'2() striking either the l, washer y17 or't e washer 18 before the member 4can be--turned too far, l A', few/.o f-tlie-more prmient features of the improved loud speaker will nowbe discussed from the standpoint of utility. It has -beenknown for many years that a good telephone receiver is one of minimum weight' quencies andthe various high fre uencyVJ and maximum ri idity. The minimum harmonics to ass through the trans ormer weight permits the iaphragm to be vibrated with more fac ity. The transformer having` been* thereon, the bracket 12"may.be fa" ened tol the ends of the hexagonal mountingbolts 13 ."and 14 which forthls purpose are threaded to receive the screws 15 and 16, 2. -J

Thenext stepin the 'assembly is the connecting up eff-the primary and :secondary leadsV (nt shawn) of the' transformer tofi'thfe four lugs of the ,terminal mounting strip 43,

- Fig. 2. Thetwo terminals to which vthe secondary, windings of the transformer are conounted c diaphragm in vibrating comes very close to the vpole pierces. It is obvious, however, that the truss diaphragm disclosed in this application 'combines maximum rigidity with minimum weight on account of its hollow interi/or. Furthermore, it. has been 4found that the weight of the diaphragmhas been decreased suliiciently topermit the added to the diaphragm at the centre in order to decrease the reluctance ofthe magnetic circuit.

This truss diaphragm may be seen in Figs. 2, 5, and 6, and comprises the separate thin discs 31 and 32, the soft iron armature 55, the rivet 56 and the washer 51. The discs 31 and 32 are prefer-ablypunched from t1n plated steel althou h any other desired metal or substance may Ee used.

As" an alternative the soft iron washer 55 may be placed below the lower diaphragm 32 in which case the pole pieces 23) and 24 are suitably shortened and a sleeve spacer may be used around the rivet 56 in order to hold the discs apart the centre in the absence of washer. 55. This construction, although somewhat more complicated from a mechanicalstand oint, has the added advantage of a stil shorter magnetic* path which may be'found desirable in certain cases.

Regarding the construction of the receiver itself it Swill be'noted that the pole pieces v2,3 and 24 lie snugly against the ends of the j permanent magnet 22 as may be seenin Figs. 3 and 5, and are-both held in position by the single screw 48. This constiiuction serves the double purpose of making/.the receiver slmple to `manufacture and easyy to assemble tweenthe magnet and the pole pieces, rea sultin ina low reluctance path and consekquent ya high flux density at the ends of the lkpole pieces, this being especially desirable for any loud speaking telephone receiver.

Regarding the arrangement for adjusting the distance between the pole pieces and diaphragm while the device is in actual operation, it may be pointed out that this-is es- 50. pecially desired on account of the great difference in the amount of volume desired by the various users of such a device. Some users prefer the loud speaker to operate with a large volume of sound and accordingly use a large amount of amplification in ordei' to attain this end. When this is done the rdiaphragm must of necessity be at some distance away from the pole pieces so that it will not strike the latter iii-vibrating. On the other hand, many users desire a relatively small volume of sound and may therefore dispense with vmuch ofthe amplification which would otherwise be used. When thisis done the receiver works most efficiently with the diaphragm fairly close to the weight of an entra soft iron armature to bediaphragm.

pole pieces. Either of these conditions may be met by merely turning the adj austing member 46-shown in the drawings.

What I claim is: '1. Ina telephone receiver, a pair of pole pieces disposed in parallel planes,'and means for adjusting the position of one in its plane and relative to the position of the/other pole iece. p 2. In a telephone receiver, a magnet having'its poles formed into tw'o substantially parallel faces, two soft iron pole pieces fitted against said faces, a single screw holding said lpole pieces in position, and a hollow non-circular member through which said screw passes and which may be turned to force said pole pieces snugly up against said l faces. V

3. In telephone receivin"I device, a diaphragm, a receiver assemlbly and a diaphragm assel'iibly, said receiver assembly having a base with screwthreads thereon, said diaphragm assembly be-ing rovided with a threaded hole into which sai receiver assembly may be -screwed so as to bring it int'o operative relation withe said diaphragm, means for adjusting the distance between one of said poles and said diaphragm, and means including toothed gears .for subse uently turning said receiver assembly bac and forth to adjust the distance between said receiver assembly and said diaphragm.`

4. In 'a telephone receiving device, a diaphragm, al receiver assembly and' a diaphragm assembly, said receiver assembly having a base with screw .threads thereon,

. said diaphragm assembly being provided with a threaded hole into which said receiver assembly may be screwed Aso as to bring it into and also makes a very good connection be-Loperative relation with said. diaphragm,

means including' toothed gears for subsequently turning said receiver assembly back and forth to adjust the distance between said receiver assembly and said diaphragm, and a friction device attached to and rotatable ,with said receiver assembly f and bearing lagainst said diaphragm assembly to maintain the adjusted position of said parts. i

5. In a telephone receivingdevice, av diaphragm assembly anda receiver assemblyV containing two pole pieces disposed in parallel planes', means for adjusting one of said pole pieces in its plane and with respect to the other pole piece, and ,means for adjusting said receiver assembly-'with Arespect to said 6.0 In a telephone receiving device, a diaphragm assembly and a receiver assembly.i

a plurality of pole pieces `on said receiver,

assembly, means foradjustin one of `said pole pieces withgrespect-to said diaphragm, 'and means for adjisting said receiver assembly with respect tosaid diaphragm.

lill) 7 .f In -a telephone receiving devioe,.a diaphragm vassembly and a receiver assembly,.

pairof pole 4pieces disposed in planes paral. lel to the axis of said diaphragm, meansfor4 moving one of said pole pieces in its plane without altering its Vrelation tosaid axis',-

andmeans for movin'g both of said pole holding said pole pieces agai and means -fof tli'en moving one of said pole` 25 pieces without altering their relation to said axis. ,e

- 9.,In :n.telephone receiver, a )ermanent magnet havingpole facesin su staintially parallel planes,-sot iron'l pole pieces fitted 20 l to saidfaces and lying in planes parallel. to said iirst planes, means comprising a nonmagnet-i cam shaped clamping member for said ,faces pieces fora limited distancewthin its plane without disturbingzsaid clamping means.

In witness whereof, I hereunto subscribe ny name this 8th day of Auv'ust, A. D., 1923.

Jenna-ERICKSON. ,l 

